Wireline operations are commonly provided with coiled tubing and an electrical cable for such wireline operations is usually housed or received within the coiled tubing for extending downhole. A wireline may be used with various instruments such as surveying and steering, electrical resistance sensing, weight-on-bit measuring tools, tachometers for drill motors, for example. These instruments are connected to the surface with a wireline for the transmission of data. The data is processed, displayed, or inputted within a computer in accordance with state of the art. Thus, it is desirable that a tool be provided for coiled tubing having a wireline extending from the surface downwardly within the coiled tubing and the associated tool for receiving and/or sending data to various downhole instruments. Further, it is desirable that a downhole tool be provided in which the wireline cable extends centrally of the tool with fluid flow down its tube being about the centrally located incline cable.
In well operations, with the insertion and retrieval of tubular materials from a well, it is not uncommon to have a tool located at the lower end of a tubing string to become stuck in the well. Rather than leave the entire tubing string in the wellbore, it is occasionally desirable to break the connection between the tool and the remaining portions of the tubing string so that with retrieval of the tubing string, only a small portion of the well is blocked by the stuck tool. A fishing tool may then be used for removal of the stuck tool. In some instances an upper portion of the tool is removed with the tubing string so that only the lower portion of the tool remains in the well.
Many tool release mechanisms are used for this purpose. The most common joints between tubing and the well tool involve a threaded interconnection or a common J-latch arrangement. The release of these joints, however, necessitates the rotation of the tubing string in order to effect release of the coupling. In coiled tubing operations, it is virtually impossible to effect rotational movement of the tubing string particularly with long horizontal sections in deviated wells. With tubing string systems other than coiled tubing systems, it may be undesirable to employ rotational movement of the string even though such rotation may be possible.
Coupling means which do not require rotation of the tubing string such as compression or Belleville springs do not provide sufficient holding force for maintaining the coupling interconnection at all times when it is desired. Release of such couplings resulting from minor impacts can lead to expensive fishing/retrieval operations which might not otherwise be required. Such couplings also require a large amount of annular space for the release mechanism.
U.S. Pat. No. 4,984,632 dated Jan. 15, 1991 shows a tool disconnect or tool release joint for a tool connected to coiled tubing. The tool release joint utilizes a hydraulic release coupling in which the release pressure can be adjusted over a wide range. Most of the disconnect system heretofore have utilized either tension or pressure to actuate the release mechanism. These disconnect systems may easily be actuated unintentionally and may be difficult to operate under certain conditions, such as long horizontal sections in deviated wells. It is desirable that tool release mechanisms have two separate operations in order to effect actuation of the release mechanism in order to minimize any inadvertent actuation of the release mechanism.
U.S. Pat. No. 5,323,853 dated Jun. 28, 1994 is directed to a downhole disconnect tool which utilizes an electrical signal to actuate the disconnect mechanism. The disconnect mechanism may also be separately actuated by hydraulic actuation. Thus, the disconnect tool may be separated or disconnected by either hydraulic actuation or electrical actuation to provide a redundancy. There is no cooperative effort between the electrical actuation and the hydraulic actuation as each operates independently of the other. Further, a separate hydraulic fluid line extending to surface is required for the operation of the hydraulic actuation.